Cisco exposes virtual servers to the SAN

Posted on November 11, 2008

-- Continuing to bring storage management services into the fabric, Cisco has turned its attention to the storage needs of virtual machines. The company announced this week that it has added new software features to its MDS 9000 Series Multilayer SAN Switches that create "VMware-optimized SANs" by bringing storage management from the physical world into the virtual arena.

The VMware-Optimized SAN feature is the result of a collaboration between Cisco and VMware to provide security, mobility, performance monitoring, and capacity planning at the virtual machine level, making it easier for storage professionals to monitor, manage, and scale SAN-attached virtual machines.

Some of the challenges inherent to deploying virtual servers in the data center are the loss of visibility, security, traffic isolation of applications, and management complexity they create. Cisco's director of product marketing for storage solutions, Rajeev Bhardwaj, says optimizing the MDS 9000 platform for VMware establishes a high-performance fabric that supports large, dense virtual machine environments by providing consistent policy, visibility, and diagnostics for virtual machines across the data center.

Cisco is using the N-Port ID Virtualization (NPIV) Fibre Channel protocol feature on the MDS 9000 platform to assign virtual machines a full identity on the SAN, exposing each virtual server to networked storage resources.

Hypervisors use NPIV to create a virtual host bus adapter (HBA) for each virtual machine. The virtual HBA is identified by the Fibre Channel port World Wide Name (pWWN) in the same way as a physical HBA, and that identity is preserved even when the virtual machine moves across physical servers.

The result is that each feature available for a physical server is available for virtual machines, including basic Fibre Channel services such as zoning and more advanced features such as troubleshooting tools, QoS, and performance monitoring.

"Virtual machines are now becoming the atomic unit of how data centers are built, and the storage infrastructure now has to adapt," says Bhardwaj. "VM-aware SANs allow users to manage and provision SANs for virtual servers just as they would physical servers."

Cindy Borovick, research vice president for IDC's Datacenter Networks service, says the VM-aware capabilities of the MDS platform could lower the barriers to deploying virtual servers in Cisco installations.

"If a customer already has an MDS switch in place, [he or she] can turn on this feature through a simple software upgrade without a significant up-front investment," says Borovick.

She says making its architectures VM-aware across the board is a necessary step in Cisco's Data Center 3.0 strategy as the company attempts to fend off challengers in the data center.

"Cisco has made a commitment that it will continue to be innovative; there are a few things they need to do to make that happen as there are a significant number of competitors like Brocade, Force 10, Woven Systems, etc., knocking at the door and making inroads into the data center," says Borovick.